Scipio ERP speaks the Agentic Commerce Protocol

Until now an agent in Scipio ERP worked for the shop owner. It found orders, fixed prices, answered the returns. With the Agentic Commerce Protocol it can also work for the buyer, and the buyer’s agent can check out in your store.

The Agentic Commerce Protocol (ACP) comes from OpenAI and Stripe. It is open source under the Apache License 2.0, the first version came out on 29 September 2025 and the current stable one is from 17 April 2026. It describes three things a store has to offer: a product feed the agent can search, a checkout the agent can drive, and order events that tell the agent what happened after the sale. The store stays the merchant of record. The payment spec says it plainly: OpenAI is not the merchant of record, your payment provider settles, refunds and handles the chargebacks.

So we built it into the core, as a new application next to the shop.

What a store answers#

Every store webapp answers ACP under its own path, /<webapp>/acp/, and publishes a discovery document at /.well-known/acp.json, so an agent finds out by itself what the store speaks. A store without a product store and web site never answers, and one switch turns all of it off.

• Checkout sessions. Create, update, complete and cancel, as the checkout spec defines them. Prices, taxes and shipping come out of the same pricing the storefront uses, so the agent sees the price a person would see. An open session expires after six hours.
• The product feed. A products.jsonl file plus its metadata, one line per sellable product out of the store’s catalog, up to 50,000 by default. In the current feed schema a product is an id plus its variants, and each variant carries its price, stock, barcodes, pictures and options. A virtual product in Scipio becomes one feed product with its variants, which is the shape the catalog has anyway.
• Payment. The agent never sees a card number. It hands the store a Stripe shared payment token, and the store charges it through its own Stripe account.
• Order events. Every change to an order that came from an agent goes out as a signed webhook. A failed delivery is retried with a growing pause, 1, 2, 4, 8 minutes and so on, up to six hours.
• An MCP binding. The same checkout is also reachable as MCP tools under /<webapp>/acp/mcp, for agents that speak MCP rather than REST.

The rules we did not change#

An ACP token is an ordinary Scipio agent token, so it is a user login with that login’s permissions and nothing more. The login needs one extra permission, ACP_CHECKOUT. Each token gets 120 calls a minute, every request can carry an idempotency key that we keep for a day, and if you set a secret, every request has to be signed and no older than five minutes.

Terms, privacy, returns and shipping policy go into every checkout session as links to the store’s own pages. The agent shows them to the buyer, not a summary of them.

Where it stops#

Payment runs through Stripe only for now. If your store takes PayPal or invoice, the agent checkout does not offer them.

ACP is young. Between the first release and the current one the spec had four more versions, and we accept all five in the API-Version header. It will change again, and we will follow it. Google’s Universal Commerce Protocol covers a lot of the same ground. More on how the two relate in two weeks.

And honestly, nobody knows yet how many people will let an agent buy for them. I would rather have the store ready when they do than explain to a customer why their agent bounced off our checkout…

ACP ships with Scipio ERP 4.0 on GitHub , under the AGPL-3.0 .